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Alternative Sources of Nutrients
Natural sources of nutrients such as manure and wastewater (sludge) can be used as an alternative in crop production. Dairy, swine, and poultry manure are valuable resources that do not have detrimental affects on the environment. There are also new developments in waste management and nutrient recovery to make the most of natural resources. With the decrease of phosphate sources, agricultural authorities have been searching for new sources of nutrients that benefit the environment. Alternative sources of nutrients can be very beneficial to the environment, especially when it comes to limiting some of the waste production and chemical run off that can occur most frequently in urban areas. Background of Nutrients There are sixteen essential nutrients required for crop production, which are usually divided into macronutrients and micronutrients1. Carbon ©, hydrogen (H) and oxygen (O) are macronutrients, abundantly available in the air. Macronutrients available in the soil are usually required in large amounts for production (taken up by the roots in ionic form) like nitrogen (N), phosphorus (P), potassium (K), sulfur (S), calcium (Ca) and magnesium (Mg). Urban Agriculture Magazine predicts that the shortage of phosphate, found in most fertilizers, will be one of the most pressing problems in coming years[2]. This has led to a huge need for alternative sources of phosphate, other than the fossil and rock where it is typically found. Agriculture experts are in support of a more efficient fertilizing technique, where in organic and inorganic fertilizers are mixed together rather than each separately. Alternative for Commercial Fertilizer One alternative source of nutrients is human excreta, which contains organic matter along with potassium, carbon, nitrogen, and phosphorus. According to Urban Agriculture Magazine, “the fertilizing equivalent of excreta is, in theory at least, nearly sufficient for a person to grow his own food.”[1] This is important in urban agriculture because large amounts of urine and other organic matter are produced in urban areas daily. If these excretions were to be collected and reused for fertilizing, it would serve as a safer alternative for soil. The difficulty with using excreta or manure as fertilizer is that it takes quite a bit more product to be efficient in providing nutrients to the soil, a larger amount than necessary for commercial fertilizer. There is not enough manure produced to supply a large percentage of nutrients, in order to meet the needs of crop production.3 Since it is an organic source, it is greatly influenced by biological processes such as mineralization and immobilization. It is important to identify the nutrient needs of a crop or plant before supplying the organic waste. 4 Health and safety measures must be taken in order for organic waste recycling within the food chain to be successful. Always consult safe methods for reusing organic waste to avoid health risks in the community. Wastewater is also a source of nutrients that can be utilized in urban agriculture efforts. According to Newsweek “in a survey of 53 countries, the International Water Management Institute (IWMI) found that the majority of produce cultivated in urban plots is irrigated with water from polluted streams, lakes or wells."[5] It appears that many farmers rely on recycled water to continually produce crops. However, skepticism still exists about the reuse of wastewater, since there are health risks associated with its use. Cultural barriers prevent it from being a regularly practiced process. References 1. Olufunke, Cofie, Stan Maessen, et al. "Waste Management for Nutrient Recovery." Urban Agriculture. Apr 2010: 3-7. 2. Olufunke, Cofie, Stan Maessen, et al. "Waste Management for Nutrient Recovery." Urban Agriculture. Apr 2010: 3-7. 3. "Fertalizer Material." Soil Nutrient Management for Maui County. n. page. Web. 12 Mar. 2014. http://www.ctahr.hawaii.edu/mauisoil/c_material.asp&xgt;. 4. Rosen, Carl, and Peter Bierman. "Using manure and compost as fertilizer for fruit and vegetable crops." University of Minnesota. (2013): n. page. Web. 12 Mar. 2014. 5. STAFF, "Wastewater Used to Irrigate Urban Agriculture."Newsweek. 13 Mar 2013: n. page. Web. 12 Mar. 2014.